Switches are usually mounted in an enclosure and incorporate an insulating base to carry an incoming line base for each phase. The circuit for each phase is completed through a pivotal knife blade which engages a corresponding contact to electrically connect the line current to the load. Switches can be fusible or non-fusible. In fusible switches the blade engages a contact which is electrically connected to a fuse clip having a fuse seated thereon. The fuse is then electrically connected to the load. U.S. Pat. Nos. 4,302,643, and 5,777,283, commonly assigned to the Square D Company, disclose a fusible switch utilizing the abovementioned construction. The disclosures of such patents are hereby incorporated herein by reference. In non-fusible switches the blade engages a contact which is directly electrically connected to the load.
Switches, and particularly fusible switches, are used in switchboards to disconnect and distribute power for commercial and industrial applications. The need arises to distribute more power through enclosures which are the same size or smaller. This requires increasing the electrical rating of the switch to carry a higher voltage and current density while decreasing the size of the enclosure housing and mounting mechanism housing the electrical parts.
Among the problems caused by decreasing the space requirements of a switch is the additional components within the switch, including the components necessary for: mounting different types of fuses; hinging the blade; engaging the end of the blade; providing springing capability to the blade hinge, blade jaw, and fuse clip; mounting the line lug and load lug; connecting the fuse clips and blade jaws with the line lug and load lugs; connecting the line bases; mounting the rotor mechanism; providing a rotor cam stop; providing a switching mechanism housing; and, connecting the switching mechanism to the switch. Multiple parts and multiple connecting hardware has resulted in increased cost, increased inventory, increased assembly time and complexity of assembly, and has reduced the flexibility for field replacement of interior components and conversion from a fusible to non-fusible switch and vice-versa. Further, decreasing the space requirements of a switch has decreased the efficiency of the switching mechanism.
Accordingly, there is a need for an effective and efficient means for providing a switch assembly and switching mechanism. One of the requirements for such a switch and switch assembly includes that the part count must be reduced and made such that parts that were once unique to a single element, are now compatible with multiple elements and uses. This will reduce inventory, supply and assembly problems. Further, the switch assembly must be economical to manufacture, the switch must be capable of being assembled easier and faster to reduce cost, field assembly and retrofit must be simplified, and the switch must have more widespread application.